The recipe looks pretty solid. I might use a Maris Otter or mild ale malt as your 2-row to give it a good, solid flavor, but that's just me. The only thing that raises a red flag for me is the mash temp. With a beer this big, you're going to end up with a pretty high FG mashing that high (definitely higher than 1.020). I'd mash this in the 152-154 range, tops, but again, that's just me.